LibUI::FFI::DrawStrokeParams.Dashes Example about libui HOT 2 CLOSED

  dashes = [
    50.0, # ink
    10.0, # skip
    10.0, # ink
    10.0  # skip
  ].pack('d*')     # array -> string

require 'libui'

UI = LibUI

UI.init

handler = UI::FFI::AreaHandler.malloc
area    = UI.new_area(handler)

brush = UI::FFI::DrawBrush.malloc.tap do |b|
  b.Type = 0
  b.R = 0.3
  b.G = 0.6
  b.B = 0.9
  b.A = 1.0
end

stroke_params = UI::FFI::DrawStrokeParams.malloc.tap do |sp|
  dashes = [
    50.0, # ink
    10.0, # skip
    10.0, # ink
    10.0  # skip
  ].pack('d*')     # here!
  ndash = 4
  offset = -50.0

  sp.Cap = UI::DrawLineCapFlat
  sp.Join = UI::DrawLineJoinMiter
  sp.MiterLimit = 10
  sp.Dashes = dashes
  sp.NumDashes = ndash
  sp.DashPhase = offset
  sp.Thickness = 10.0
end

handler_draw_event = Fiddle::Closure::BlockCaller.new(0, [1, 1, 1]) do |_, _, area_draw_params|
  UI.draw_new_path(UI::DrawFillModeWinding).then do |path|
    UI.draw_path_new_figure(path, 128.0, 25.6)
    UI.draw_path_line_to(path, 230.4, 230.4)
    UI.draw_path_line_to(path, 230.4 - 102.4, 230.4 + 0.0)
    UI.draw_path_bezier_to(path,
                           51.2, 230.4,
                           51.2, 128.0,
                           128.0, 128.0)
    UI.draw_path_end(path)

    area_draw_params = UI::FFI::AreaDrawParams.new(area_draw_params)
    UI.draw_stroke(area_draw_params.Context, path, brush.to_ptr, stroke_params)
    UI.draw_free_path(path)
  end
end

handler.Draw         = handler_draw_event
# These callbacks are not protected from GC. It's really not very good.
handler.MouseEvent   = Fiddle::Closure::BlockCaller.new(0, [0]) {}
handler.MouseCrossed = Fiddle::Closure::BlockCaller.new(0, [0]) {}
handler.DragBroken   = Fiddle::Closure::BlockCaller.new(0, [0]) {}
handler.KeyEvent     = Fiddle::Closure::BlockCaller.new(0, [0]) {}

box = UI.new_vertical_box
UI.box_set_padded(box, 1)
UI.box_append(box, area, 1)

main_window = UI.new_window('Basic Draw Dash', 300, 300, 1)
UI.window_set_margined(main_window, 1)
UI.window_set_child(main_window, box)

UI.window_on_closing(main_window) do
  UI.control_destroy(main_window)
  UI.quit
  0
end
UI.control_show(main_window)

UI.main
UI.quit